Shield and actuator for needles

ABSTRACT

A shieldable needle assembly includes a needle guard slidably movable along a needle cannula from a proximal position where the distal end of the needle cannula is exposed to a distal position where the distal end of the needle cannula is safely shielded within the needle guard. A hinged arm assembly connects the needle guard assembly to needle hub. A trigger is articulated to the needle hub at a location proximally of the hinged arm. Distally directed digital forces cause the trigger to rotate such that the trigger urges the hinged arm from a collapsed condition to an extended condition.

FIELD OF THE INVENTION

The subject invention relates to safety shields for preventingaccidental sticks with sharp medical implements.

DESCRIPTION OF THE PRIOR ART

An accidental stick with a used needle cannula can transmit disease. Asa result, most prior art needle cannulas are used with a safety shieldfor preventing accidental sticks.

A shieldable needle assembly is taught in U.S. Pat. No. 5,348,544. Thisprior art needle assembly includes a needle cannula having a proximalend and a pointed distal end. Portions of the needle cannula adjacentits proximal end are securely retained in a needle hub. The needle hubis releasably threadedly engaged with a luer collar on a syringe.

The prior art shieldable needle assembly includes a needle guard whichis slidably movable along the needle cannula from a proximal positionsubstantially adjacent the hub to a distal position surrounding thedistal end of the needle cannula. The needle guard includes a plasticcap configured for sliding along the needle cannula and a metallic clipsecured in the cap and biased against needle cannula as the cap is movedin a distal direction. However, once clip passes distally beyond theneedle cannula, it will resiliently move toward an unbiased condition toprotectively cover the distal end of the needle cannula.

The prior art needle assembly further includes a hinged arm assembly forinitiating movement of the needle guard and for controlling the amountof movement of the needle guard along the needle cannula. The hinged armassembly includes a proximal segment hingedly connected to the needlehub and a distal segment articulated to portions of the proximal segmentremote from the hub. The distal segment of the hinged arm assembly isfurther articulated to the needle guard.

In the collapsed needle exposing condition the needle guard issubstantially adjacent to the hub. However, distally directed digitalforces may be exerted on the hinged arm assembly to urge the hinged armassembly into an extended condition in which its segments aresubstantially linearly arrayed and generally parallel to the needlecannula. This extension of the hinged arm assembly will generate slidingdistal movement of the needle guard along the needle cannula. Thedimensions of segments of the hinged arm assembly are selected to permitdistal portions of the needle guard to move beyond the distal end of theneedle cannula and to prevent proximal portions of the needle guard frommoving beyond the distal end of needle cannula.

Movement of hinged arm assembly from the collapsed condition to theextended condition is facilitated by a biased hinge intended to propelthe needle guard distally. Thus, the user of the prior art shieldableneedle assembly need not push the hinged arm assembly entirely into theextended condition.

There is a desire to make further improvements over the prior artshieldable needle assembly described in U.S. Pat. No. 5,348,544. Forexample, it is desired to provide a more visually apparent actuationstructure for unmistakable encouraging the single handed-single digitactuation for which the needle shield assembly is designed. It isfurther desired to permit actuation with even a shorter stroke ofmovement of the user's finger. This latter objective is desirable inthat it facilitates easier actuation of the shield.

SUMMARY OF THE INVENTION

The subject invention is directed to an easily shieldable needleassembly. The assembly includes a needle having a proximal end and apointed distal end. The proximal end of the needle may be securelymounted in a needle hub, which in turn may be mounted releasably on ahypodermic syringe or other medical implement. The assembly furtherincludes a needle guard that is slidably movable along the needlecannula from a proximal position where the distal end of the needle isexposed, to a distal position where the distal end of the needle issafely shielded by the needle guard. The needle guard may include aplastic cap and a metallic clip. The clip may be securely retainedbetween the cap and the needle, and may be configured for slidableengagement with the needle as the guard moves toward its distalposition. However, portions of the clip are configured to protectivelycover the pointed distal end of the needle after sufficient distalmovement of the needle guard.

The shieldable needle assembly of the subject invention further includesa hinged arm assembly connecting the needle guard with structure spacedproximally from the distal end of the needle. For example, the hingedarm assembly may include a proximal segment articulated to structurenear the proximal end of the needle and a distal segment articulated tothe needle guard. The proximal and distal segments of the hinged armassembly may be articulated to one another and may include biasing meansfor selectively urging the needle guard toward its distal position. Thebiasing means may be stable in both the proximal position of the needleguard and in the distal position thereof, such that the biasing means isnot pre-stressed in either of these extreme positions of the hinged armassembly. The hinged arm assembly is dimensioned to permit the needleguard to protectively shield the pointed distal end of the needle whenthe hinged arm assembly is extended. However, these dimensions alsoprevent the needle guard from moving distally beyond the needle.

The shieldable needle assembly further includes a trigger articulated toa location proximally of the hinged arm assembly. The trigger includesan actuating surface dimensioned and configured for convenient digitalactivation by a thumb or forefinger of the hand holding the medicalimplement to which the shieldable needle assembly is connected. Thetrigger further may include a cam edge or cam surface for engagingportions of the hinged arm assembly and urging the hinged arm assemblyfrom the collapsed condition into the extended condition. The triggermay be dimensioned, configured, textured and/or colored to be clearlydistinguishable from other portions of the shieldable needle assemblyand to provide a clear indication of its intended function.

In use, distally directed digital forces may be exerted on the actuatingsurface of the trigger to cause the trigger to rotate about its hingedconnection. These digital forces will cause the cam surface or edge ofthe trigger to engage proximally facing surfaces of the hinged armassembly and to cause the hinged arm assembly to quickly move from itscollapsed condition into its extended position. The trigger may beconfigured to ensure that camming forces are exerted throughout therange of movement of the hinged arm assembly. Alternatively, the cam maymerely urge the hinged arm assembly into a position where the springmeans will urge the hinged arm assembly into the extended positionwithout the benefit of continued pressure by the cam of the trigger. Inother embodiments, movement of the hinged arm assembly from thecollapsed to the extended condition may be attributable to a combinationof spring forces and digital forces transmitted through the trigger.

The trigger can provide an enhanced mechanical advantage, and henceeasier actuation, while also providing a clearer indication of preferredoperation of the shieldable needle assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a prior art shieldable needleassembly.

FIG. 2 is a side elevational view of a shieldable needle assembly of thesubject invention in a ready-to-use condition.

FIG. 3 is a cross-sectional view taken along line 3--3 in FIG. 2.

FIG. 4 is a side elevational view similar to FIG. 2, but showing theshieldable needle assembly in an intermediate position.

FIG. 5 is a side elevational view similar to FIGS. 2 and 4 but showingthe shieldable needle assembly in a fully extended condition forprotectively shielding the distal tip of the needle cannula.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

While this invention is satisfied by embodiments in many differentforms, there is shown in the drawings and will be herein described indetail a preferred embodiment of the invention with the understandingthat the present disclosure is to be considered exemplary of theprinciples of the invention and is not intended to limit the scope ofthe invention to the embodiment illustrated. The scope of the inventionwill be measured by the appended claims and their equivalents.

Adverting to FIG. 1, a needle shield assembly 112 includes a needleguard 140 which is slidably movable along needle cannula 114 from aproximal position substantially adjacent to hub 120 to a distal positionsurrounding distal end 118 of needle cannula 114. The needle shieldassembly is connected to syringe 122. Needle guard 140 includes aplastic cap 142 configured for sliding along the needle cannula. Needleguard 140 further includes a metallic clip 144 secured in cap 142 andbiased against the needle cannula as cap 142 is moved in a distaldirection. When clip 144 passes distally beyond needle cannula 114, theclip will resiliantly move toward an unbiased condition to protectivelycover distal end 118 of the needle cannula.

The prior needle assembly further includes a hinged arm assembly 154 forinitiating movement of needle guard 144 and for controlling the amountof movement of the needle guard along the cannula. Hinged arm assembly154 includes a proximal segment 156 hingedly connected to the needle huband the distal segment 158 articulated to portions of the proximalsegment 156 remote from hub 120. Distal segment 158 of the hinged armassembly is further articulated to the needle guard.

FIG. 1 shows the prior art hinged arm assembly 154 in a collapsedcondition such that needle guard 140 is substantially adjacent to hub120. However, distally directed digital forces may be exerted on hingedarm assembly 154 to urge the hinged arm assembly into an extendedposition in which segments 156 and 158 are substantially linearlyarrayed and generally parallel to the needle cannula. The extension ofhinged arm assembly 154 will generate sliding distal movement of needleguard 140 along the needle cannula. The dimensions of segments 156 and158 of the hinged arm assembly are selected to permit distal portions ofneedle guard 140 to move beyond distal end 118 of the needle cannula andto prevent proximal portions of needle guard 140 for moving beyonddistal end 118 of needle cannula.

Movement of hinged arm assembly 154 from the collapsed condition,illustrated in FIG. 1, to the extended position is facilitated by abiasing hinge intended to propel the needle guard distally. Thus, theuser of the prior art needle shield assembly need not push the hingedarm assembly 154 entirely into the extended position.

A shieldable needle assembly in accordance with the subject invention isidentified generally by the numeral 12 in FIGS. 2-6. Shieldable needleassembly 12 includes a needle cannula 14 having opposed proximal anddistal ends 16 and 18 and a lumen extending continuously therebetween.Proximal end 16 of needle cannula 14 is securely embedded in a unitarilymolded thermoplastic hub 20. Hub 20 is configured for releasableconnection to a hypodermic syringe 22.

Syringe 22 includes a tubular syringe barrel 24 having a proximal end(not shown), an opposed distal end 28 and a fluid receiving chamber 30.Tip 34 projects distally from distal end 28 of syringe barrel 24 andincludes a passage 36 extending therethrough for communication withchamber 30. A generally cylindrical luer collar 38 concentricallysurrounds tip 34 and includes an array of threads for releasableengagement with projections on hub 20 of shieldable needle assembly 12.

Shieldable needle assembly 12 further includes a needle guard assembly40 having a cap 42 and a clip 44 which is preferably metallic. Cap 42includes opposed proximal and distal end walls 46 and 48 and a chamber50 therebetween. Proximal and distal end walls 46 and 48 each include aneedle receiving aperture therethrough such that cap 42 can be slidablyengaged over needle cannula 14. Thus, cap 42 can be slidably moved froma proximal position substantially adjacent needle hub 20 to a distalposition where cap 42 substantially surrounds and encloses distal tip 18of needle cannula 14.

Metallic clip 44 of needle guard assembly 40 includes a proximal leg 52with an aperture through which needle cannula 14 extends. Metallic clip44 further includes a distal leg 53 bent to be substantially orthogonalto needle cannula 14. Portions of metallic clip 44 between proximal anddistal legs 52 and 53 are resiliently deflected such that distal leg 53is biased against the exterior of needle cannula 14. Thus, clip 44 willslide with cap 42 along needle cannula 14. Portions of metallic clip 44between the proximal and distal legs thereof are configured to bias thedistal leg of metallic clip 44 against needle cannula 14. Thus, distalleg 53 of metallic clip 44 will slide against needle cannula 14 asneedle guard assembly 40 is slidably advanced from its proximal positionshown in FIG. 2 to its distal position shown in FIG. 5. However, aftersufficient distal movement, distal leg 53 of clip 44 will advance beyonddistal end 18 of needle cannula 14. Metallic clip 44 will thenresiliently return toward an undeflected or less deflected condition inwhich distal leg 53 protectively covers distal end 18 of needle cannula14. Thus, metallic clip 44 will prevent a proximal movement of needleguard assembly 40 that could re-expose tip 18 of needle cannula 14.

Shieldable needle assembly 12 further includes a hinged arm assembly 54having a proximal segment 56 and a distal segment 58. Proximal segment56 of hinged arm assembly 54 has a proximal end articulated to needlehub 20 and a distal end articulated to the proximal end of distalsegment 58. Distal segment 58 of hinged arm assembly 54 is furtherarticulated to needle guard assembly 40. The articulation betweenproximal segment 56 and hub 20 may be by a spring hinge, such as theover center hinge shown in U.S. Pat. No. 5,348,544. Such a hingedevelops stored energy during initial stages of opening and then usesthat stored energy to complete the opening. The articulation of distalsegment 58 of hinged arm assembly 54 to needle guard assembly 40 mayinclude a flexible connection to portions of cap 42 near proximal endwall 46.

Hinged arm assembly 54 can be folded into a collapsed condition as shownin FIG. 2 such that needle guard assembly 40 is substantially adjacenthub 20. However, hinged arm assembly 54 can be extended to permit needleguard assembly 40 to slidably advance toward distal end 18 of needlecannula 14. Proximal and distal segments 56 and 58 of hinged armassembly 54 are dimensioned relative to one another to permit needleguard assembly 40 to slidably advance into surrounding relationship withdistal end 18 of needle cannula 14. However advancement of needle guardassembly 40 distally beyond needle cannula 14 is positively presented byhinged arm assembly 54.

Shieldable needle assembly 12 further includes a trigger 60 articulatedproximally of articulated arm assembly 54 for rotation about an axistransverse to needle cannula 14, as defined by hinge 65, andsubstantially parallel to the rotational axes of hinged arm assembly 54.Trigger 60 further includes a preferably convexly shaped, arcuate camedge 62 at locations thereon remote from the articulated connection toneedle hub 20. Additionally, trigger 60 includes an actuating face 64facing substantially proximally in the articulated position depicted inFIG. 2. Actuating face 64 is preferably a non-planer surface such as asurface having a plurality of ridges 66 for facilitating digitalmanipulation of trigger 60. Surface irregularities other than ridges 66may be provided for achieving these purposes.

FIG. 2 shows shieldable needle assembly 12 in its ready-to-usecondition. In this condition needle guard assembly 40 is disposed in aproximal position on needle cannula 14 substantially adjacent hub 20.Additionally, in this ready-to-use condition, hinged arm assembly 54 issubstantially collapsed such that proximal and distal segments 56 and 58thereof are adjacent one another. Still further, in this ready-to-usecondition shown in FIG. 2, trigger 60 is aligned substantiallyorthogonal to needle cannula 14 with camming edge 62 of trigger 60 beingin abutting contact with portions of hinged arm assembly 54substantially adjacent the articulation between proximal and distalsegments 56 and 58 thereof and, preferably, primarily in contact withthe proximal segment.

Shieldable needle assembly 12 is used by exerting distally directeddigital pressure on actuating face 64 of trigger 60. Ridges 66 onactuating face 64 prevent the thumb or forefinger exerting the digitalpressure from sliding off trigger 60. These distally directed digitalforces on trigger 60 cause trigger 60 to rotate about its hingedconnection to hub 20 to further cause cam edge 62 of trigger 60 to exertforces on portions of proximal segment 56 of hinged arm assembly 54remote from hub 20. These forces on proximal segment 56 of hinged armassembly 54 cause proximal segment 56 to rotate about its hingedconnection to hub 20 and further cause hinged arm assembly 54 to movetoward an extended condition.

Needle guard assembly 40 will slidably advance distally along needlecannula 14 as hinged arm assembly 54 is extended, as shown in FIG. 4.Additionally, arcuate cam edge 62 of trigger 60 will slide alongproximal segment 56 of hinged arm assembly 54 as both the proximalsegment 56 and trigger 60 rotate. Thus, even though the relativeorientation of proximal segment 56 of hinged arm assembly 54 changes,continued distally directed forces will be exerted thereon by cammingedge 62 of trigger 60.

Continued distally directed digital forces on trigger 60 will propelneedle guard assembly 40 toward distal end 18 of needle cannula 14 andinto the shielding position shown in FIG. 5. This propulsion of needleguard assembly 40 distally may be facilitated by biasing forces exertedby the over center hinge connection of proximal segment 56 of hinged armassembly 54 to hub 20. In the fully extended condition of hinged armassembly 54, distal leg 53 of metallic clip 44 will have passed beyonddistal end 18 of needle cannula 14. Clip 44 then will resiliently returntoward an undeflected condition such that distal leg 53 covers distalend 18 of needle cannula 14 to prevent re-exposure of distal end 18.Thus, extended hinged arm assembly 54 will prevent needle guard assembly40 from moving distally beyond needle cannula 14 and metallic clip 44will prevent needle guard assembly 40 from moving proximally into aposition where distal end 18 of needle cannula 14 may be re-exposed.

Trigger 60 of shieldable needle assembly 12 defines a clearlyidentifiable location for exertion of the distally directed digitalforces. Additionally, trigger 60 enables the distally directed digitalforces to be exerted from a location further from distal end 18 ofneedle cannula 14. The combined effect of continuous distal forcesexerted by camming edge 62 of trigger 60 and the biasing effect of thehinged connection between arm assembly 54 and hub 20 enables rapidshielding operation.

What is claimed is:
 1. A shieldable needle assembly comprising:a needlehaving proximal and distal ends; a hub securely mounted around saidproximal end of said needle; a needle guard slidably mounted on saidneedle and movable from a proximal position where said distal end ofsaid needle is exposed to a distal position where said needle guardsafely guards said distal end of said needle; a hinged arm articulatedto said hub and to said needle guard and being movable from saidcollapsed condition where said needle guard is in said proximal positionto an extended condition where said needle guard is in said distalposition on said needle; and a trigger articulated to said hub at alocation proximally of said hinged arm, said trigger including a camsurface spaced from said hub and slidably engaged with said hinged armsuch that articulation of said trigger toward said hinged arm urges saidhinged arm into said extended condition and said needle guard into saiddistal position on said needle.
 2. The shieldable needle assembly ofclaim 1, wherein said hinged arm includes a proximal segment articulatedto said hub and a distal segment articulated to said needle guard, saidproximal and distal segments of said hinged arm being articulated to oneanother, said cam surface of said trigger being slidably engagedprimarily with said proximal segment of said hinged arm.
 3. Theshieldable needle assembly of claim 1, wherein said trigger includes aproximal face having a non-planar surface configuration for facilitatingexertion of digital pressure thereon.
 4. The shieldable needle assemblyof claim 1, wherein said cam surfaces comprises a convex edge at alocation on said trigger remote from the articulation of said trigger tosaid hub.
 5. The shieldable needle assembly of claim 1, wherein said hubincludes opposed proximal and distal ends, said hinged arm beingarticulated to said distal end of said hub.
 6. The shieldable needleassembly of claim 5, wherein said proximal end of said hub comprisesmeans for threaded engagement with a luer collar, said trigger beingarticulated to said hub at a location between said proximal and distalends thereof.
 7. The shieldable needle assembly of claim 1, wherein saidneedle guard comprises a cap and a metallic clip engaged in said cap,said metallic clip being biased against said needle when said needleguard is in said proximal position, such that stored energy in said clipurges said clip over said distal end of said needle when said needleguard is in said distal position.
 8. The shieldable needle assembly ofclaim 1, wherein at least a portion of said hinged arm is unitary withsaid hub.
 9. The needle assembly of claim 1, wherein at least a portionof said needle guard is unitary with at least said distal segment ofsaid hinged arm.
 10. A single handedly actuatable shield assembly for aneedle, said needle comprising an elongate needle cannula having opposedproximal and distal ends and a hub securely mounted around said proximalend of said needle cannula, said shield assembly comprising:a shieldhingedly connected to said hub and movable from a first condition wheresaid distal end of said needle cannula is exposed to a second positionwhere said distal end of said needle cannula is enclosed by said shield;and a trigger hingedly connected to said hub at a location spaced fromsaid shield, portions of said trigger spaced from said hub beingengageable with portions of said shield for urging said shield into saidsecond position where said distal end of said needle cannula isenclosed.
 11. The assembly of claim 10, wherein said shield comprises ahinged arm articulated to said hub and a needle guard connected to saidhinged arm, said trigger being engageable with said hinged arm of saidshield.
 12. The assembly of claim 11, wherein said hinged arm comprisesa proximal segment defining portions of said hinged arm articulated tosaid hub, said hinged arm further comprising a distal segmentarticulated to said proximal segment and defining portions of saidhinged arm connected to said needle guard, said hinged arm beingsubstantially collapsed in said first condition of said shield and beingsubstantially linearly extended in said second condition of said shield.13. The assembly of claim 12, wherein said proximal segment of saidhinged arm is articulated to said guard.
 14. The assembly of claim 10,wherein said trigger includes an arcuate cam edge at a location thereonspaced from the hinged connection of said trigger to said hub, saidarcuate cam edge defining portions of said trigger that are slidablyengageable with said shield.
 15. The assembly of claim 14, wherein saidtrigger includes an actuating surface having surface irregularities forfacilitating digital manipulation, said actuating surface facing awayfrom said needle cannula.